URT1CA0EM. 741 



water, or all submerged and linear. Flowers minute, usually solitary 

 in each axil, between 2 minute bracts varying much in size and some- 

 times wholly wanting. Male flowers consisting of a single stamen 

 with a conspicuous filament ; the females of a sessile or stalked ovary, 

 with 2 erect or recurved styles. Fruit from \ to 1 line in diameter, 

 the lobes either rounded or keeled on the edge, or surrounded by a 

 narrow wing. 



In shallow waters or wet mud, dispersed almost all over the globe. 

 Abundant in Britain. Fl. the whole season. It has been variously 

 divided into from 2 to about 20 supposed species, from slight differences 

 in the size and form of the fruits, the direction of the styles, in the 

 bracts, etc., or from the presence or absence of the upper obovate leaves; 

 but the distinctive characters which have been given, all fail when 

 applied to a large number of specimens collected in different parts of 

 the world. 



LXIX. THE NETTLE FAMILY. URTICACEJS. 



Herbs, or, in exotic genera, trees or shrubs, with leaves usually 

 rough or stinging, more or less conspicuous stipules, and small, 

 herbaceous, unisexual flowers. Perianth in the males regular and 

 simple. Stamens as many as segments of the perianth and oppo- 

 site to them, or rarely fewer. Perianth of the females often less 

 divided. Ovary free or rarely adherent to the perianth, with a 

 single ovule, and 1 or 2 styles or stigmas. Fruit small, 1-seeded, 

 dry or rarely succulent. Seed with or witbout albumen, the ra- 

 dicle pointing upwards. 



A very large Order, chiefly tropical, of which the few British species 

 give a very inadequate idea. It is readily distinguished from the 

 Spurge family by the single-seeded fruit, from the Catkin family by 

 the regular perianth of the male flowers. 



Erect herbs. Leaves opposite 1. Nettle. 



Erect or procumbent herb. Leaves alternate 2. Pellitory. 



Tall twiner. Leaves opposite 3. Hop. 



Among exotic genera in cultivation may be mentioned the Hemp 

 (Cannabis), which, although an erect herb, is in many respects allied 

 to the Hop ; the Fig (Ficus), in which the flowers are collected in 

 great numbers withinside a succulent receptacle, popularly called the 

 fruit ; and the Mulberry (Morus), in which the flowers are collected 

 in heads on the outside of a receptacle, and become succulent as the 

 fruit ripens. 



